max3.2

Hi,

thinking about getting an OBC for my 91' 964. I read some stuff and think its possible, but have a few questions left, maybe someone else hast done it or done a similar thing..Main problem is that I do no want to remove my steering wheel because I never done that and don't really like tampering with the airbag system.

1) Can you remove the lower steering column cover without removing the steering wheel? I can get to the bolts, But I don't know if thats enough...But as far as I know, the lower cover has to be adapted...

2) If 1 is possible, can you remove the top dash to access the wiring to the mirror and wiggle out the old tachometer

Cheers!

ToreB

It is completely possible to remove the tacho without removing the steering wheel or column. I have done it over 50 times. See here for details,:
https://www.bergvillfx.com/obcrepair
Cheers, Tore

ToreB

Obc retrofit:
https://p-car.com/diy/obc/

max3.2

The provided link looks like the 993 built. Thanks for the first one though. I heard that 964s have the wiring in. Regarding the initial question, I worked my way around a bit:

1) Not possbile, steering wheel blocks the cover. So it has to come off to install the new switch.

2) Its possible, and a fairly easy removal. Routing the wire to the mirror is something I did not check yet, but it looks ugly. Does someone has experience with this task?

Nikolaus964

I have done the modification myself (cause I got hold of a European Rev Counter displaying KM/H instead of miles/hour) but wonder how you plan to operate the OBC? On my car I removed the Airbag steering wheel to change the left side indicator stalk to the one that includes the OBC control. Removing the Steering wheel on the Porsche is no big deal -and makes the job easier just make sure to disconnect the battery for at least 30min before you start working on the Airbag and use a permanent pen to mark the steering wheel position before you pull the wheel of the spline.

Routing the wire to the mirror and installing the sensor is on my todo list (for quiet a while already) - so I am interested in feedback as well...



good luck with your project

Nikolaus

nathan1

It's a very simple upgrade, have done it to a couple of my 964's. On a NON OBC 964 the tach can be removed without removing the steering wheel. The OBC tach however will NOT come out without removing the wheel as it has a greater depth than the standard tach. Removing the steering wheel is VERY simple and no big deal. Ultimately you have to do it anyway as you need to install the stalk which controls the OBC. All you need to source is the tach itself, the stalk and the steering column trim that allows for 4 stalks vs. the standard 3. The wiring for the OBC is already present and it literally just plugs in (this is NOT the case for a 993!). The only function which does not work is the outside temperature as you will need to install the sensor in the drivers mirror if you want that to work. The other functions (speed, MPG, distance to empty, etc) work out of the box. It's a great upgrade!

max3.2

Did not change the Tach yet since I will let my mech remove the wheel. Everyone says its easy, but I don't feel like doing it myself the first time with the airbag in. Removal of old one and testing the new one works with the wheel, I don't see a way to get the new one in with the wheel. I'll have it changed on Wednesday.

Regarding the temp sensor, I installed it, here's the how to (part list below). Images follow:

1) The plug comes without wire or pins. I used .5mm silicon wire as stated in the wiring scheme. Only had red and black though. For the pins I used Speaker ISO which are a direct fit, Porsche couldn't supply anything here. I did 5ft of wire so I had something to work with

2) Disassemble mirror, install sensor. Thats straight forward.

3) Remove inside door panel. Unlock mirror from door by undoing the hex bolt. Pull new wire through from below. Careful with sharp, non-chamfered edges along the way. Once the wire is in the door, reassemble mirror.

4) Driver footwell: Disassemble cover on the left (2 screw at frunk lever), locate T8 (10 pin connecter) and the large cable running to the door grommet. I ran a long cabletie through the grommet, attached the new wire in the door to that cabletie and pulled everything through. Reassemble door.

Now to the fun part: Get the new wires into the connector T8. Porsche left almost no length on the wire so working down in the footwell. No fun for normal sized people.

5) Undo T8. That gives you a little bit of space. Pin 9/10 are free, thats where the OBC expects the Temp sensor. Open female connector, all wires pins will come out, so note the colors.

6) I found some wire end sleeves 6mm to be a direct fit. Soldered them onto the new wire, added a little hot glue for insulation, thats optional.

7) Reassemble connector with the new wire inside. Thats the MOST annoying part to do and takes patience.

8) Success!



Parts, about 100$ from Porsche:
928 641 342 00
N 014 760 3
928 641 142 00
911 612 817 00
443 906 232

max3.2

I just completed the build, sadly no pictures since it was done in the shop at my mechanic and we had some delay due to some failing shifter bushings.
Its an easy replace once the wheel is off. Just the plug for the lever can be hard to find deep under the dash but its possible. Even though I bought a new cover, I ended up dremeling a hole in the old since the new was a bad fit. Not pretty but its gonna work for now.

I really like the upgrade. Nice to see the speed in kmps for Germany. If you can score the parts cheap its well worth it. Temp sensor works like a breeze!